DE3608469A1 - HYDRAULIC SYSTEM - Google Patents

HYDRAULIC SYSTEM

Info

Publication number
DE3608469A1
DE3608469A1 DE19863608469 DE3608469A DE3608469A1 DE 3608469 A1 DE3608469 A1 DE 3608469A1 DE 19863608469 DE19863608469 DE 19863608469 DE 3608469 A DE3608469 A DE 3608469A DE 3608469 A1 DE3608469 A1 DE 3608469A1
Authority
DE
Germany
Prior art keywords
line
pressure
directional
pump
pumps
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
DE19863608469
Other languages
German (de)
Inventor
Gottfried Dipl Ing Olbrich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Priority to DE19863608469 priority Critical patent/DE3608469A1/en
Priority to EP87101602A priority patent/EP0236750B1/en
Priority to DE8787101602T priority patent/DE3778738D1/en
Publication of DE3608469A1 publication Critical patent/DE3608469A1/en
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/165—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for adjusting the pump output or bypass in response to demand
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/351—Flow control by regulating means in feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/353—Flow control by regulating means in return line, i.e. meter-out control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/413—Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
    • F15B2211/41518—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve being connected to multiple pressure sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5151—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a directional control valve
    • F15B2211/5152—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a directional control valve being connected to multiple pressure sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/528—Pressure control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6052—Load sensing circuits having valve means between output member and the load sensing circuit using check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Operation Control Of Excavators (AREA)
  • Control Of Positive-Displacement Pumps (AREA)

Description

Stand der TechnikState of the art

Die Erfindung geht aus von einer Hydraulikanlage nach der Gattung des Hauptanspruchs. Bei derartigen bekannten An­ lagen ist es bisher noch nicht gelungen, diese mit optimaler Energiebilanz zu betreiben, da die richtige Zuschaltung weiterer Pumpen zur Hauptpumpe Schwierigkeiten bereitet.The invention is based on a hydraulic system according to the Genus of the main claim. In such known An locations have not yet succeeded, with optimal Operate energy balance because the right connection further pumps to the main pump causes difficulties.

Vorteile der ErfindungAdvantages of the invention

Die erfindungsgemäße Hydraulikanlage mit den kennzeich­ nenden Merkmalen des Hauptanspruchs hat demgegenüber den Vorteil, daß bei einem Mehrpumpensystem eine optimale Energiebilanz erreichbar ist. Die Zuschaltung weiterer Pumpen wird bedarfsorientiert und stetig, d. h. weich durchgeführt. Hierzu ist nur eine einzige Druckwaage zur Regelung zweier oder mehrerer Pumpenförderströme not­ wendig, mit bedarfsabhängiger Stromregelung beider Pumpen und Neutralumlaufsteuerung derselben. Der Hauptver­ braucher kann in einem load-sensing-Kreis angeordnet sein, die Nebenverbraucher ebenfalls oder in einem open center-System. The hydraulic system according to the invention with the character features of the main claim has the Advantage that an optimal with a multi-pump system Energy balance is achievable. The connection of further Pumping becomes demand-oriented and constant, i.e. H. soft carried out. There is only one pressure compensator for this Regulation of two or more pump delivery flows not necessary agile, with demand-based current control of both pumps and neutral circulation control thereof. The main ver User can be arranged in a load sensing circuit be the secondary consumer also or in an open center system.  

Besonders zweckmäßig ist es in einem Zweipumpensystem, wenn bei kleinem Strombedarf nur die erste Pumpe För­ derdruck bringt, während die zweite Pumpe bei geringem Neutralumlaufdruck fördert. Erst bei einem Strombedarf, der den der ersten Pumpe übersteigt, wird auch die zweite Pumpe mit auf Druck gefahren und der Summenstrom dem be­ tätigten Verbraucher zugeführt.It is particularly useful in a two-pump system if only the first pump För the pressure brings, while the second pump at low Neutral circulation pressure promotes. Only when there is a need for electricity which exceeds that of the first pump, also becomes the second Pump driven with pressure and the total current to be supplied consumers.

Zeichnungdrawing

Zwei Ausführungsbeispiele der Erfindung sind in der Zeich­ nung und in der nachfolgenden Beschreibung näher erläutert. Die beiden Zeichnungen zeigen jeweils eine Hydraulikanlage in schematischer Darstellung.Two embodiments of the invention are in the drawing tion and explained in more detail in the following description. The two drawings each show a hydraulic system in a schematic representation.

Beschreibung der AusführungsbeispieleDescription of the embodiments

Im Ausführungsbeispiel nach Fig. 1 sind mit 10 und 11 zwei Pumpen bezeichnet, von denen die Pumpe 10 die erste Pumpe ist, die Pumpe 11 die zweite. Beide Pumpen saugen Druck­ mittel aus einem Behälter an, die Pumpe 10 fördert es in eine Leitung 12, die Pumpe 11 in eine Leitung 13. An die Leitung 13 ist eine Leitung 14 angeschlossen, die in die Leitung 12 mündet. In der Leitung 14 ist ein Rück­ schlagventil 15 angeordnet, das sich in Richtung von der Leitung 13 zur Leitung 12 zu öffnen vermag. An die Lei­ tung 14 ist ein Druckbegrenzungsventil 16 angeschlossen.In the exemplary embodiment according to FIG. 1, 10 and 11 denote two pumps, of which the pump 10 is the first pump, the pump 11 the second. Both pumps draw pressure medium from a container, the pump 10 pumps it into a line 12 , the pump 11 into a line 13 . A line 14 is connected to line 13 , which opens into line 12 . In the line 14 a return check valve 15 is arranged, which can open in the direction of the line 13 to the line 12 . At the Lei device 14 , a pressure relief valve 16 is connected.

Die Leitung 13 führt zu einer Druckwaage 17 mit den Schalt­ stellungen I, II, III, die fließenden Übergang aufweisen. An die eine Seite der Druckwaage führt eine von der Lei­ tung 12 ausgehende Steuerleitung 19, an die entgegengesetzte Seite eine Steuerleitung 20, die zu einer Leitung 21 führt. Von der einen Längsseite der Druckwaage führt eine Leitung 22 zur Leitung 14, wo sie stromabwärts des Rückschlag­ ventils 15 mündet, von der entgegengesetzten Seite führt eine Leitung 23 zur Rücklaufleitung 24. Die Leitung 21 geht am Ende des Ventilblocks in die Rücklaufleitung 24 über.The line 13 leads to a pressure compensator 17 with the switching positions I, II, III, which have a smooth transition. On one side of the pressure compensator leads a control line 19 starting from the line 12 , on the opposite side a control line 20 leading to a line 21 . From one longitudinal side of the pressure compensator, a line 22 leads to line 14 , where it opens downstream of the check valve 15 , from the opposite side a line 23 leads to the return line 24 . The line 21 merges into the return line 24 at the end of the valve block.

Im Ventilblock befinden sich drei Wegeventile 26 bis 28, von denen nicht weiter bezeichnete Verbraucherleitungen zu entsprechenden Verbrauchern führen. In jeder Arbeits­ stellung eines Wegeventils befindet sich eine Meßblende, die entsprechend den Wegeventilen die Indexzahlen A und B tragen. Von jedem Wegeventil führt eine Leitung 29 bis 31 zur Rücklaufleitung, und eine Steuerleitung 32 bis 34 zur Leitung 21; diese ist eine Signalleitung oder eine load-sensing-Leitung. An jeder Mündungsstelle der Lei­ tungen 32 bis 34 in die Leitung 21 befindet sich ein Wechselventil 35 bis 37. Diese Ventile haben den Zweck, den jeweils höchsten, an einem Verbraucher herrschenden Druck in die Leitung 21 und damit an die rechte Stirn­ seite der Druckwaage 17 zu signalisieren. Auf diese Seite der Druckwaage wirkt auch eine Regelfeder 39 ein.In the valve block there are three directional control valves 26 to 28 , of which consumer lines (not further specified) lead to corresponding consumers. In each working position of a directional control valve there is an orifice plate which carries the index numbers A and B according to the directional control valves. A line 29 to 31 leads to the return line from each directional control valve, and a control line 32 to 34 leads to line 21 ; this is a signal line or a load sensing line. At each mouth of the lines 32 to 34 in the line 21 there is a shuttle valve 35 to 37 . These valves have the purpose of signaling the highest pressure prevailing at a consumer in the line 21 and thus on the right front side of the pressure compensator 17 . A control spring 39 also acts on this side of the pressure compensator.

Die Druckwaage 17 hat den Zweck, die Pumpen 10 und 11 be­ darfsorientiert zu schalten. Wenn kein Verbraucher zu­ geschaltet ist (wie gezeichnet), befindet sich die Druck­ waage 17 in ihrer Schaltstellung I, da in der Leitung 21 kein Druck herrscht, wohl aber in der Leitung 19, und zwar ein Druck, der höher ist als die Kraft der Regelfeder 39. Das von beiden Pumpen geförderte Druckmittel fließt nun über die Leitung 23 zum Behälter 24.The pressure compensator 17 has the purpose of switching the pumps 10 and 11 as required. If no consumer is switched on (as drawn), the pressure balance 17 is in its switching position I, since there is no pressure in line 21 , but it is in line 19 , namely a pressure that is higher than the force of the Standard spring 39 . The pressure medium delivered by both pumps now flows via line 23 to container 24 .

Wird ein Verbraucher zugeschaltet - beispielsweise durch Verstellen des Wegeventils 28 - so baut sich in der Lei­ tung 34 entsprechend dem Regeldruckgefälle an der Meß­ blende 28 A ein Druck auf, welcher über das Rückschlag­ ventil 37 in die Leitung 21 übertragen wird. Hat dieses Druckgefälle einen bestimmten Wert erreicht, was bedeutet, daß der Druck in der Leitung 21 ansteigt und der Verbraucher mehr Druckmittel braucht, dann wird entsprechend diesem Druck und der Kraft der Regelfeder 39 die Druckwaage in Richtung ihrer Schaltstellung II verstellt. Dabei fördert die Pumpe 11 immer noch in die Rücklaufleitung. Ist der Stromverbrauch gerade so groß, wie er dem Förderstrom von Pumpe 10 entspricht, hat die Druckwaage die mittlere Stellung II eingenommen, d. h. die Pumpe 11 fördert immer noch in die Rücklaufleitung. Erst mit weiter zunehmender Verstellung (Öffnung) der Meßblende 28 A wird auch die Pumpe 11 zugeschaltet, da das sich verringernde Regel­ druckgefälle an der Meßblende die Druckwaage 17 in Schalt­ stellung III verschiebt. In der Stellung III kann kein Druckmittel mehr in die Leitung 23 und damit in die Rück­ laufleitung 24 fließen, sondern der Förderstrom beider Pumpen fließt über die Leitung 14 bzw. 12 zum Verbraucher.If a consumer is switched on - for example by adjusting the directional control valve 28 - a pressure builds up in the line 34 corresponding to the control pressure drop at the metering orifice 28 A , which is transmitted via the check valve 37 into the line 21 . If this pressure drop has reached a certain value, which means that the pressure in line 21 rises and the consumer needs more pressure medium, then the pressure compensator is adjusted in the direction of its switching position II in accordance with this pressure and the force of the control spring 39 . The pump 11 still feeds into the return line. If the power consumption is just as large as it corresponds to the flow of pump 10 , the pressure compensator has assumed the middle position II, ie the pump 11 is still pumping into the return line. Only with further increasing adjustment (opening) of the orifice plate 28 A , the pump 11 is also switched on, since the decreasing control pressure drop on the orifice plate moves the pressure compensator 17 into the switching position III. In position III, no more pressure medium can flow into line 23 and thus into the return line 24 , but the delivery flow of both pumps flows via line 14 or 12 to the consumer.

Wird beispielsweise auch noch das Wegeventil 26 zugeschal­ tet und herrscht dort ein höherer Verbraucherdruck als am anderen Verbraucher, so steigt der Druck in der Lei­ tung 32 über den in der Leitung 34 an, so daß nun der Druck aus der Leitung 32 an die rechte Stirnseite der Druckwaage signalisiert wird. In die Zuführungsleitung von der Leitung 12 beispielsweise zum Wegeventil 27 kann ein Strombegrenzungsventil 40 eingesetzt sein, das den maximalen Förderstrom zum Verbraucher begrenzt.If, for example, the directional control valve 26 is also switched on and there is a higher consumer pressure than at the other consumer, the pressure in the line 32 rises above that in the line 34 , so that the pressure from the line 32 now reaches the right end face the pressure compensator is signaled. A flow limiting valve 40 can be inserted into the supply line from line 12, for example to directional control valve 27 , which limits the maximum flow to the consumer.

Auf die oben beschriebene Weise erreicht man eine be­ darfsorientierte stetige Zuschaltung der zweiten Pumpe 11 zur ersten Pumpe. Es können natürlich auch noch wei­ tere zusätzliche Pumpen auf diese Weise zugeschaltet wer­ den. Die Druckwaage regelt auch den Druck.In the manner described above, a steady-state connection of the second pump 11 to the first pump can be achieved. Of course, other additional pumps can also be switched on in this way. The pressure compensator also regulates the pressure.

Beim Ausführungsbeispiel nach Fig. 2 sind gleiche Teile wie beim vorherigen Ausführungsbeispiel wieder mit den­ selben Ziffern bezeichnet. Dieses Ausführungsbeispiel unterscheidet sich gegenüber dem vorherigen vor allem dadurch, daß es sich hier um ein open center-System han­ delt, d. h. die Wegeventile - sie sind nun mit 50 bis 52 bezeichnet - weisen in der gezeichneten Mittelstellung eine durchgehende Verbindung 54 zur Rücklaufleitung 24 auf. Dafür entfällt in diesem Ausführungsbeispiel die Leitung 21, da die Besonderheit hier das Wegeventil 50 ist, das außer der open center-Stellung I auch eine Zwi­ schenstellung II aufweist, die eine Übergangsfunktion von open center auf load sensing-Technik hat, d. h. wenn an das Wegeventil 50 ein Verbraucher angeschlossen ist, wird hier der Lastdruck über eine Leitung 55 an die Druckwaage 17 herangeführt. Diese Leitung entspricht also der Leitung 21 des vorherigen Ausführungsbeispiels. Die Pumpe 10 dient hier sowohl für die Versorgung des Hauptverbraucher als auch für den kleinen Strombedarf der Nebenverbraucher an den Wegeventilen 51, 52. Wie im vorherigen Ausführungsbeispiel dient die Pumpe 11 durch entsprechende Betätigung der Druckwaage 17 wieder zur Deckung des Spitzenbedarfs des Hauptverbrauchers, welcher am Wegeventil 50 angeschlossen ist.In the exemplary embodiment according to FIG. 2, the same parts as in the previous exemplary embodiment are again identified by the same numbers. This embodiment differs from the previous one mainly in that it is an open center system, ie the directional valves - they are now labeled 50 to 52 - have a continuous connection 54 to the return line 24 in the center position shown . For this purpose, the line 21 is omitted in this exemplary embodiment, since the special feature here is the directional control valve 50 which, in addition to the open center position I, also has an intermediate position II, which has a transition function from open center to load sensing technology, ie when the Directional control valve 50 a consumer is connected, the load pressure is brought here to the pressure compensator 17 via a line 55 . This line thus corresponds to line 21 of the previous exemplary embodiment. The pump 10 serves here both for supplying the main consumer and for the small power requirement of the secondary consumers on the directional control valves 51 , 52 . As in the previous exemplary embodiment, the pump 11 again serves to cover the peak demand of the main consumer, which is connected to the directional control valve 50 , by corresponding actuation of the pressure compensator 17 .

Eine Besonderheit besteht darin, daß in der Förderleitung 12 zwei verstellbare Drosseln 56, 57 angeordnet sind. Die Drossel 57 bewirkt, daß durch den im Neutralumlauf durch den Wegeventilblock zu den Leitungen 54 und 24 fließende Strom ein Druckabfall entsteht, der nach Über­ schreiten einer Δ p-Schwelle die Druckwaage öffnet und der Reststrom der beiden Pumpen über sie abfließt. Gleich­ zeitig ist die Drossel 57 bestimmend für den zum Wege­ ventil 52 fließenden Maximalstrom, wenn dieses betätigt ist. Es ist somit auch möglich, den vollen Summenstrom zu einem Nebenverbraucher, z. B. 52 zu bringen. Durch die spezielle Verknüpfung der Pumpenleitung mit der Neutralumlaufleitung 54 kann dieser Großstrom-Neben­ verbraucher beliebig weit hinten im Wegeventilblock an­ geordnet sein. Mit der Drossel 56 hingegen kann der zum Wegeventil 51 fließende Maximalstrom justiert werden. Da­ mit wird außer der Maximalstrombegrenzung zu den Wege­ ventilen 51 und 52 erreicht, daß bei einem Ölstrombe­ grenzungswert, der gleich oder kleiner dem von der Pumpe 10 ist, bei Betätigung dieser Wegeventile auch nur die Pumpe 10 gegen Druck fördert, während die Pumpe 11 bei Neutralumlaufdruck arbeitet.A special feature is that two adjustable throttles 56 , 57 are arranged in the delivery line 12 . The throttle 57 has the effect that a pressure drop arises from the current flowing through the directional valve block to the lines 54 and 24 in neutral circulation, which opens the pressure compensator after a Δ p threshold has been exceeded and the residual flow of the two pumps flows through them. At the same time, the throttle 57 is determining for the maximum current flowing to the directional valve 52 when it is actuated. It is therefore also possible to transfer the full total flow to a secondary consumer, e.g. B. 52 to bring. Due to the special linkage of the pump line with the neutral circulation line 54 , this large flow auxiliary consumer can be arranged as far back in the directional valve block as desired. With the throttle 56, however, the maximum current flowing to the directional control valve 51 can be adjusted. Since with the maximum flow limitation to the directional valves 51 and 52 is achieved that at an oil flow limit value that is equal to or less than that of the pump 10 , when actuating these directional valves, only the pump 10 promotes pressure, while the pump 11 at Neutral circulation pressure works.

Claims (5)

1. Hydraulikanlage mit mehreren Pumpen für die Versorgung mehrerer Verbraucher über eine gemeinsame Druckleitung, denen jeweils ein Wegeventil vorgeschaltet ist, wobei der an einem Verbraucher herrschende Lastdruck ermittelt und in eine Steuerleitung zwecks Signalverarbeitung übertra­ gen wird, dadurch gekennzeichnet, daß den Pumpen (10, 11) eine einzige Druckwaage (17) zugeordnet ist, die bei ent­ sprechendem Druckanstieg in der Steuerleitung (21, 55) die andere(n) Pumpe(n) stetig der Druckleitung zuschaltet entsprechend der Änderung des Regeldruckgefälles an einer Meßblende (26 A bis 28 A) im Wegeventil.1. Hydraulic system with several pumps for supplying several consumers via a common pressure line, each of which has a directional control valve upstream, the load pressure prevailing at a consumer being determined and transmitted to a control line for signal processing, characterized in that the pumps ( 10 , 11 ) is associated with a single pressure compensator ( 17 ) which, when the pressure in the control line ( 21 , 55 ) increases accordingly, continuously switches on the other pump (s) to the pressure line in accordance with the change in the control pressure drop on a measuring orifice ( 26 A to 28 A) in the directional valve. 2. Anlage nach Anspruch 1, dadurch gekennzeichnet, daß alle Pumpen vorzugsweise einen gemeinsamen Anschluß (23) zur Rücklaufleitung (24) haben und daß sämtliche Wegeven­ tile in Neutralstellung gesperrt sind.2. Plant according to claim 1, characterized in that all pumps preferably have a common connection ( 23 ) to the return line ( 24 ) and that all Wegeven tiles are locked in the neutral position. 3. Anlage nach Anspruch 1, dadurch gekennzeichnet, daß die Wegeventile (50 bis 52) in Neutralstellung einen Durchlauf zum Behälter haben (open center System) und daß in der Förderleitung zwei Drosseln (56, 57) ange­ ordnet sind, zwischen denen eine Leitung (58) abzweigt, die an die open center-Leitung (54) führt (Fig. 2). 3. Plant according to claim 1, characterized in that the directional control valves ( 50 to 52 ) have a pass to the container in the neutral position (open center system) and that in the delivery line two throttles ( 56 , 57 ) are arranged, between which a line ( 58 ) branches off, which leads to the open center line ( 54 ) ( Fig. 2). 4. Anlage nach Anspruch 3, dadurch gekennzeichnet, daß ein Wegeventil neben der open center-Stellung eine Zwi­ schenstellung zur Umschaltung von open center auf load­ sensing aufweist.4. Plant according to claim 3, characterized in that a directional valve next to the open center position a two switch position for switching from open center to load has sensing. 5. Anlage nach Anspruch 3 und 4, dadurch gekennzeichnet, daß die Steuerleitung (55) in Grundstellung des besonderen Wegeventils (50) mit der Druckleitung stromabwärts von Drossel (56) verbunden ist und bei betätigtem Wegeventil auf den Druckabgriffspunkt nach der internen Meßblende umschaltet.5. Plant according to claim 3 and 4, characterized in that the control line ( 55 ) in the basic position of the special directional control valve ( 50 ) with the pressure line downstream of the throttle ( 56 ) is connected and switches to the pressure tap point after the internal orifice when the directional control valve is actuated.
DE19863608469 1986-03-14 1986-03-14 HYDRAULIC SYSTEM Ceased DE3608469A1 (en)

Priority Applications (3)

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DE19863608469 DE3608469A1 (en) 1986-03-14 1986-03-14 HYDRAULIC SYSTEM
EP87101602A EP0236750B1 (en) 1986-03-14 1987-02-06 Hydraulic system
DE8787101602T DE3778738D1 (en) 1986-03-14 1987-02-06 HYDRAULIC SYSTEM.

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DE3844399A1 (en) * 1988-12-30 1990-07-12 Rexroth Mannesmann Gmbh Variable-displacement pump for a plurality of consumers which can be actuated independently of one another
DE4018972A1 (en) * 1990-06-13 1991-12-19 Rexroth Mannesmann Gmbh Infinitely variable pump system - can supply several hydraulic users and is regulated by varying load pressures
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GB2387674B (en) * 2002-04-20 2005-09-07 Agco Sa Load sensing hydraulic system
GB2390875A (en) * 2002-07-17 2004-01-21 Bamford Excavators Ltd Fluid management system
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WO2011044870A1 (en) * 2009-10-12 2011-04-21 Ixetic Bad Homburg Gmbh Hydraulic pump arrangement
DE102012011400A1 (en) * 2012-06-08 2013-12-12 Hydac System Gmbh Hydraulic system for safe pressure supply of at least one consumer
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EP0236750B1 (en) 1992-05-06
EP0236750A3 (en) 1989-09-06
DE3778738D1 (en) 1992-06-11
EP0236750A2 (en) 1987-09-16

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